a.This test method describes a means for measuring the kinematic viscosity of transparent and opaque liquids such as new and in-service lubricating oils using a microchannel viscometer. b.The range of viscosity capable of being measured by the test method is from 10 to 350 mm2/s measured at 40 C. The measurement takes place at 40 C and kinematic viscosity is directly obtained. No temperature extrapolations or density corrections are necessary. c.This test method is specifically tailored to obtaining a rapid, direct, temperature-stabilized measure of the kinematic viscosity of liquids in the field in real-time and without the use of solvents or chemical cleaning agents. As such it should not be viewed as a replacement for laboratory-based viscometers.
The method provides a means for a reliable field determination of kinematic viscosity in a hand-portable device, self-contained, operating on batteries, and does not require solvents or chemicals for cleaning, even for device setup. Field use implies that the liquid may be very opaque, such as an in-service engine oil. The device may be cleaned with a shop rag, and requires only 50 microliters of sample for operation. As such the device provides a unique service to a range of industries where it is impractical to have a capillary-bath based kinematic viscometer and/or difficult or undesirable to obtain chemicals of any sort in order to determine the kinematic viscosity of their liquid of interest. The device is currently used in a walk-around or portable fashion where the operator walks to the asset of interest or to the vicinity of the asset of interest, places it on the shop floor or a flat surface, and initiates a measurement via an on button and following a series of instructions on an LCD screen. The operator may carry the device with them in their vehicle when checking viscosity status at multiple sites by simply placing the device (typical weight less than 2 kilograms, batteries inclusive) in their vehicle without further precaution, arrive at the site, and carry the viscometer with them from the vehicle to the sampling points of interest. Examples of such industries include many marine-based systems where a laboratory does not exist on-board, mines where handheld/portable equipment is needed for on-the-spot determination of asset viscosity, and large industrial plants where a walk-around inspection of oil sumps greatly increases efficiency. Previously, for many of these users, a direct reading of kinematic viscosity was not available, even though most specifications stipulate a range of kinematic viscosity must be adhered to in the machinery being monitored, for example. These users must currently rely on only occasional kinematic viscosity readings, which may be months apart in time for sea vessels. During this time such users to not have a validated means for their, in many cases, required daily inspection of the viscosity of their critical propulsion engine lubrication systems. As to the method itself, there is currently no known standard which contemplates a microchannel which may be disassembled and re-assembled from measurement to measurement, as is the case for this device. Further, there is no known microchannel-based viscometer which is open to air on two sides, which has been standardized for viscosity measurement. Thus, a design which employs these features, as here, has no validated standard currently, and yet is in use in a variety of industries due to its applicability to their needs for a field-based kinematic viscometer. That is why it is critical to create a standard for such a method of kinematic viscosity measurement.
Keywordsmicrochannel; Hele-Shaw flow; field-based device
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development